In John's rewriting of Genesis, the resurrection of Jesus completes the creation story. The week of the Genesis creation was complete as Jesus rested ("was buried") on the seventh day, the Sabbath. Then Jesus presented himself alive to his friends and followers early in the morning following the Sabbath. Over time they realized that they were now involved in a new creation week marked by this "eighth day" resurrection. Gradually, the traditions and commands associated with Sabbath were transferred to Sunday, referred to as "the first day" (Mark 16:2 and John 20:19) and "the Lord's Day" (Rev 1:10).
-- p.119, Christ Plays in Ten Thousand Places by Eugene Peterson